Status of an endangered subspecies: the peninsular pronghorn at Baja California     

Jorge Cancino  Alfredo Ortega-Rubio  Jos A. Sanchez-Pacheco 《Journal of Arid Environments》1996,32(4):463-467

During November 1993, we traversed by ground and by air the Vizcaíno Desert, the last redoubt of the peninsular pronghorn (Antilocapra americana peninsularis). A total of 29 h of aerial census was performed and a total of 1900 km²were covered by ground, totalling 400 man hours of survey. At present the peninsular pronghorn population consists of 175 individuals, and inhabits an area of approximately 5000 km². Because of the impossibility of controlling its activities over such an area and because of the present small population size, we propose to manage part of the population in semi-captivity at Mesa de la Choya island, with the objective of assuring the survival of this subspecies, the most endangered mammal in Mexico.  相似文献   

南极半岛地区气温与南极海冰涛动、ENSO的联系   总被引：5，自引：1，他引：5       下载免费PDF全文

程彦杰  陆龙骅  卞林根  汪瑛 《极地研究》2003,15(2):121-128

使用南极半岛Orcadas等台站的气温多年观测资料 ,分析了南极半岛气温和周围海冰以及ENSO的初步联系。结果表明 ,南极半岛地区的气温变化可以反映南极海冰涛动的变化特征 :气温距平和南极半岛附近海冰距平存在密切的负相关 ,和罗斯海外围区域的海冰距平存在正相关关系 ,能够较好地反映出南极半岛气温与南极海冰涛动以及ENSO之间的紧密联系。当南极半岛地区气温偏低 (高 )时 ,南极半岛周围海冰偏多 (少 ) ,罗斯海外围海冰偏少 (多 ) ,赤道中东太平洋海温偏高 (低 ) ,可能出现ElNino(LaNina)。另外 ,南极半岛当年 1 0月的气温距平对预测次年 1月的Nino3区海温异常具有重要参考价值  相似文献   

Future hydro-meteorological drought of the Johor River Basin,Malaysia, based on CORDEX-SEA projections     

Mou Leong Tan  Liew Juneng  Fredolin T. Tangang  Ngai Weng Chan  Sheau Tieh Ngai 《水文科学杂志》2019,64(8):921-933

Water scarcity issues in the Johor River Basin (JRB) could affect the populations of Malaysia and Singapore. This study provides an overview of future hydro-meteorological droughts using climate projections from an ensemble of four Coordinated Regional Climate Downscaling Experiments – Southeast Asia (CORDEX-SEA) domain outputs under the Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios for the 2021–2050 and 2071–2100 periods. The climate projections were bias corrected using the quantile mapping approach before being incorporated into the Soil and Water Assessment Tool (SWAT) hydrological model. The Standardized Precipitation Index (SPI) and Standardized Streamflow Index (SSI) were used to examine the meteorological and hydrological droughts, respectively. Overall, future annual precipitation, streamflow, and maximum and minimum temperatures are projected to change by about ?44.2 to 24.3%, ?88.7 to 42.2%, 0.8 to 3.7ºC and 0.7 to 4.7ºC, respectively. The results show that the JRB is likely to receive more frequent meteorological droughts in the future.  相似文献   

Urban annexation of the rural: kebun culture in Malaysia     

Eric C. Thompson 《Singapore journal of tropical geography》2020,41(1):136-153

‘Kebun culture’ is a distinctive, emergent form of rural sensibility and social-economic relations in Malaysia. As a contribution to theories of ‘planetary’ or thoroughgoing urbanization, the ethnographic evidence presented in the article illustrate a case of urban annexation of rurality, in which kebun (orchards) are detached from the social organization of rural villages and incorporated into urban-centered Malay society. Kebun, as productive land with non-rice crops, have traditionally been associated with rural kampung (village). In the late twentieth century, thoroughgoing urbanization, driven by both rural-to-urban migration and in situ urbanization of rural kampung, simultaneously produced a social disintegration of Malay kampung and increasingly urban-oriented Malay society. The kebun, which previously was an ancillary part of kampung social ecology has become dissociated from kampung and instead operates as an annex of urban-centered social lives. Kebun are also distinctively individuated rather than communal socio-economic projects. In both reserve lands and kampung areas, urban-based Malays and rural-to-urban return migrants are involved in kebun projects, through which they engage with nostalgic notions of rurality, but without the social entanglements of kampung social relations. At the same time, through kebun projects, urban Malay subjects enter into new social relations, albeit ones marked by commodification.  相似文献   

A brief summary of Dr. G. V. Rao’s research interests     

Yeong-Jer Lin  James T. Moore  Jack Fishman 《Natural Hazards》2007,41(3):381-386

A brief summary of Dr. G. V. Rao's research interests is presented. Many of his earlier studies were in conjunction with the summer Monsoon Experiment of 1979 (MONEX-79). These included: 1) the structure of the Somali jet based on aerial observations; 2) sea-level air trajectories over the equatorial Indian Ocean; 3) structural features of the east African low-level flow; 4) effects of Indian Ocean surface temperature anomaly patterns on the summer monsoon circulations; 5) structures of the monsoon low-level flow over the Arabian Sea; 6) characteristics and momentum-flux budgets of the Arabian Sea convective bands; and 7) evaporation and precipitation over the Arabian Sea during the monsoon seasons. Dr. Rao's research efforts in recent years had focused on case studies of mesocyclones spawned by tropical cyclones (TCs) in Florida using Doppler radar data and a mesoscale numerical model. These included: 1) research on tornadic mesocyclones spawned by TC Earl in 1998; 2) documentation of subtle differences between tornadic and non-tornadic mesocyclones in TC Floyd in 1999; and 3) numerical simulation of the tornadic environment observed in peninsular Florida during TC Earl in 1998. Preliminary findings show that the supercells' cold pools interacted with an existing boundary resulting in increased baroclinicity and horizontal vorticity, and a maximization of the tornado production potential by the updrafts. The model successfully simulated the mesoscale features of the mesocyclones and the tornadic environment observed during TC Earl. A 24 h simulation of accumulated rainfall within the inner domain agreed well with the observed precipitation pattern over the region.  相似文献   

Concentrations of trace elements in marine fish and its risk assessment in Malaysia   总被引：1，自引：0，他引：1  

Agusa T  Kunito T  Yasunaga G  Iwata H  Subramanian A  Ismail A  Tanabe S 《Marine pollution bulletin》2005,51(8-12):896-911

Concentrations of trace elements (V, Cr, Mn, Co, Cu, Zn, Ga, Se, Rb, Sr, Mo, Ag, Cd, Sn, Sb, Cs, Ba, Hg, Tl, Pb and Bi) were determined in muscle and liver of 12 species of marine fish collected from coastal areas in Malaysia. Levels of V, Cr, Mn, Co, Cu, Zn, Ga, Sr, Mo, Ag, Cd, Sn, Ba and Pb in liver were higher than those in muscle, whereas Rb and Cs concentrations showed the opposite trend. Positive correlations between concentrations in liver and muscle were observed for all the trace elements except Cu and Sn. Copper, Zn, Se, Ag, Cd, Cs and Hg concentrations in bigeye scads from the east coast of the Peninsular Malaysia were higher than those from the west, whereas V showed the opposite trend. The high concentration of V in the west coast might indicate oil contamination in the Strait of Malacca. To evaluate the health risk to Malaysian population through consumption of fish, intake rates of trace elements were estimated on the basis of the concentrations of trace elements in muscle of fish and daily fish consumption. Some specimens of the marine fish had Hg levels higher than the guideline value by US Environmental Protection Agency (EPA), indicating that consumption of these fish at the present rate may be hazardous to Malaysian people. To our knowledge, this is the first study on multielemental accumulation in marine fish from the Malaysian coast.  相似文献   

Time preference of small-scale fishers in open access and traditionally managed reef fisheries     

《Marine Policy》2014

Individuals with high discount rates are likely not partial to conservation because they are unwilling to sacrifice short term benefits for potentially higher gains in the future. Many reef fisheries worldwide are open access, and fishers under open access systems are theorized to discount the future at an infinite rate. In contrast, fishers in a customary managed fishery can be expected to be more long term oriented, and thus possibly have lower discount rates. The present study tests this hypothesis by eliciting the discount rates of fishers in an open access small-scale reef fishery, and compares these rates to those of fishers in a customary managed reef fishery. Results indicate that fishers in both open access and traditionally managed reef fisheries have high annual discount rates that are on average over 200%. Contrary to expectations, fishers under an open access system are not associated with higher discount rates compared to customary management. It also appears that a larger proportion of open access fishers are more long-term oriented than those in the customary managed fishery, which is encouraging for the future conservation and sustainability of open access fisheries resources.  相似文献   

马来西亚在南海的战略利益分析     

姜丽  范晓婷  王琦  公衍芬 《广东海洋大学学报》2014,(2):29-32

采用实证分析法,分析了对马来西亚南海战略利益及政策,认为马来西亚南海政策具有较为明显的务实性、矛盾性、两面性特点,未来具有解决南海问题多边化、国际化的趋向,我国对此发展趋向应予以高度重视。  相似文献   

Larval fish assemblages in a tropical mangrove estuary and adjacent coastal waters: Offshore-inshore flux of marine and estuarine species   总被引：1，自引：0，他引：1  

A.L. Ooi  V.C. Chong 《Continental Shelf Research》2011,31(15):1599-1610

A total of 92,934 fish larvae representing 19 families were sampled monthly from the Sangga Kecil estuary (Matang Mangrove Forest Reserve) and adjacent coastal waters from May 2002 to October 2003. Larval fish assemblages were numerically dominated by Gobiidae (50.1%) and Engraulidae (38.4%). Canonical Correspondence Analysis (CCA) revealed that the larval fish assemblages, including their ontogenetic stages, differed between the mangrove estuary and adjacent offshore waters, and that salinity, turbidity and zooplankton food are the major environmental factors structuring the larval fish assemblages. Estuarine preflexion gobiid larvae were ubiquitous in the coastal and estuarine waters. Larval stages of euryhaline species that were spawned in offshore waters, such as Engraulidae and Clupeidae, were largely advected into mangrove areas at the postflexion stages. Larvae of other euryhaline fishes (Sciaenidae, Blenniidae and Cynoglossidae) that may have been spawned inside the estuary were, however, exported to offshore waters. Given that the collective number of juvenile and adult fish families in the Matang estuary was 53, while the number of larval families was only 17, the former is quite disconnected from the existing larval fish population in the estuary.  相似文献   

Establishment of Avicennia marina mangroves on accreting coastline at Sungai Haji Dorani, Selangor, Malaysia     

Noraini Mohd. Tamin  Rozainah Zakaria Roslan Hashim  Yu Yin 《Estuarine, Coastal and Shelf Science》2011,94(4):334-342

Avicennia marina saplings were established within a restoration area at Sg. Hj. Dorani, Malaysia between May and August 2010. Sapling establishment was achieved following the construction of segmented and hard breakwater as mitigating measure against coastal erosion. Geostructures known as brush faschines were installed within the restoration area as secondary sediment and seed traps. There was a steady increase in the sand content of the soil from 5% in November 2008 to 18% in May 2010. The dominant soil content was silt but it fluctuated and declined slightly over the same period, between 80% in November 2008 and 72% in May 2010. The accreting shoreline behind the breakwater had stabilised within 18 months. Subsequently, the first batch of A. marina wild seedlings or wildings was established on the mud surface in September 2009. Only about 10% of these wildings survived and showed high survival rate (90%) over the next eight months. Wildings that were naturally established near mother trees showed good growth performance. No wilding was established after the fruiting season in August 2010 as all seeds that were dispersed into the restoration area were washed away by September 2010. Tall, A. marina wild saplings (1 m) planted within the restoration area showed higher survival rate (80%) compared to planted saplings of Rhizophora apiculata (30%). Final planting of a thousand 1 m tall A. marina wild saplings was carried out from June 2010, in clumps of 20 and in 1 m × 1 m spacing. By the end of September 2010 clusters of regenerating A. marina mangroves about 1.5 m tall were successfully established on the accreting coastline.  相似文献